SAT & ACT Punctuation Rules – Cheat Sheet & Practice
January 20, 2025
Commas, semicolons, colons, and em-dashes: what are we supposed to do with all this punctuation? And how could you, a simple student, possibly learn all the rules you need to learn for the SAT and ACT before you take it? In reality, it’s much simpler than you might think. In this article, I’m going to break down the most essential punctuation rules that will help you sail through the SAT and ACT without getting frustrated and feeling like you don’t know anything.
You may also want to check out 275 SAT Vocabulary Words You Must Know.
What’s the point of punctuation rules, anyway?
Pause.
Before we get started breaking down the punctuation rules themselves, I want you to consider this question. The answer will help guide you in remembering how and when to use punctuation.
The point of punctuation—periods, commas, semi-colons, colons, em-dashes, and parenthesis—is to help your reader understand how to read your sentences. Punctuation actually follows and describes the natural flow of speaking, pausing, and breathing that we do when we speak in the English language.
Rule 0: Punctuation is kind of intuitive
So, the first unofficial/official rule that I want you to remember is this: punctuation serves to create pauses in your sentences at natural places where a reader should pause to help the sentence make sense. You use verbal punctuation all the time when you talk. Let’s look at an example of a sentence without any commas:
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
→ Imagine if you will if all your words ran together in one big long train without you ever breathing stopping or adding inflection that would be completely unhinged don’t you think?
When in doubt, sound it out. Go back and read that example sentence above. Where would you naturally pause to make the sentence make sense? If you ever find yourself stuck on how to punctuate a sentence, read the sentence silently to yourself and find the places where you might naturally pause. More often than not, you’ll put a comma in those places.
Let’s use the first paragraph of this article as our first example.
Exercise: Read the sentences out loud, and see how your pauses line up with the punctuation
I’m going to copy and paste the first sentences of this article below. Then, I want you to read the sentences out loud to yourself, paying attention to where the punctuation guides you to pause. And don’t just run through it; read it in a nice way, a formal way, an articulate way, as if you wanted someone to really understand what you were saying.
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Sentence 1: Commas, semicolons, colons, and em-dashes: what are we supposed to do with all this punctuation?
Sentence 2: And how could you, a simple student, possibly learn all the rules you need to learn for the SAT and ACT before you take it?
—
In Sentence 1, where did you pause? After each item in the list? And after the colon (:) and before the word “what,” correct?
And in Sentence 2, where did you pause? Before and after the words “a simple student,” right?
Each of those moments describes a different punctuation rule that we’ll dive into below.
Remember, you already instinctively know how and when to pause while reading and speaking. We’re just going to place some rules around the pausing you already do. The goal of these grammatical rules is to help you organize your thinking, and to help you make the right choice every time.
Rule 1: Items in a List
One of the simplest punctuation rules is using commas to separate items in a list. When you have a list of three or more items, you need to place a comma between each item in the list to separate those things.
Look at the list in Sentence 1 again: Commas, semi-colons, colons, and em-dashes.
Each item is followed by a comma. The final item in the list is included by using the word “and,” because all of these items belong together. The conjunction “or” is also used to indicate that the items in a list do not all belong together or to connote the idea of choice.
For example: You can choose between french fries, onion rings, or a side salad.
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
Notice that only the items in the list have a comma after them. The conjunctions “and” and “or” never have a comma after them. They’re not items in the list, so they don’t need to have a verbal pause after them. Remember the pause trick here as an easy tool.
How weird would it sound if you were a waiter and you told someone they could have “french fries, onion rings, or,” and then you took an intentional pause and then said, “a side salad with your meal.” You would never do that. In that same way, you would never put a comma after the word “and” or “or” in a list. Don’t confuse yourself here.
Important Grammar Tip: Keep It Simple, Students
This is the right time to tell you my favorite grammar tip. You can remember it with the acronym KISS: Keep It Simple, Students. (We used to say “Keep It Simple, Stupid,” but that’s not very nice! You’re not stupid. You’re learning.)
Just remember: grammar rules are meant to help, not hurt your writing. If you find yourself overthinking something, let go of the urge to throw commas all over the place. More often than not, they’re not necessary.
Rule 2: Using a colon to set off a list (or other information)
Let’s go back to Sentence 1 and take a look at how to use a colon.
First off, what is a colon? Go to your keyboard, find the L key, slide one key to the right, and find the key with both the colon (:) and the semicolon (;).
I like to remember the colon as the eyes to a smiley 🙂 and the semicolon as the eyes to a wink ;). Because a wink is like a semi-smile. Get it?
Now, what does a colon do?
A colon is used to set off, set apart, or introduce a list or an idea. It can also provide emphasis or introduce a quotation. It serves to separate an independent clause from other information to which the independent clause is related.
Hint: An “independent clause” is another way of saying a “full sentence.” An independent clause is independent. It has a subject, verb, and object. It does not need other information in order to communicate a complete idea.
You can think of those two dots in a colon like an open portal. They open the door to new information.
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
Exercise:
Practice writing some sentences that use colons to introduce a list and commas to separate the items in a list.
Examples:
He already had everything at home to bake his cake: flour, eggs, sugar, and milk.
There were many indigenous tribes that made their homes on the land that is now western Pennsylvania, including: Iroquois, Munsee Delaware, Lenape Delaware, Erie, Shawnee, and Susquehannock.
You can also use a colon to introduce information that is not a list. Try writing some sentences that use a colon to showcase a piece of information.
Examples:
If there was one thing Larry had prepared for, it was this: the cold.
Nobody anticipated how hard the virus would hit the country, but that’s exactly what it grew into: a pandemic.
If there’s one person you absolutely have to call on Mother’s Day, it’s her: your mother!
Rule 3: Using a semicolon to separate two independent clauses
In the previous rule, we talked about how a colon is used to separate an “independent clause” from other discrete pieces of information that cannot stand on their own.
In Rule 3, I’ll show you how to use a semicolon to join two independent clauses that could stand on their own. For some reason, though, these two sentences really want to be attached to one another; they want to be one long sentence. It might be cringe; who am I to judge? Semicolons are the relationship glue that serves to shove together two independent clauses that might otherwise be separated by a period; you decide when those clauses belong together.
See what I did there? The previous three sentences all use the rule we’re talking about.
I’m not trying to trick you, but I am trying to show you how these rules can show up in regular writing. Let’s look at those sentences, what makes them independent clauses, and how you can use them to practice with semicolons on your own.
Let’s break out two of the sentences onto their own lines, and have you identify the key parts of each sentence.
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Sentence 1: For some reason, though, these two sentences really want to be attached to one another; they want to be one long sentence.
Sentence 2: Semicolons are the relationship glue that serves to shove together two independent clauses that might otherwise be separated by a period; you decide when those clauses belong together.
—
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
Exercise: Identifying the parts of an independent clause
Choose one of the sentences above as your starting point. Find the semicolon. Remove the semicolon and replace it with a period. Now, you have two independent clauses. How do you know?
In each sentence, underline the subject, verb, and object. (*We’ll provide you with the answers at the bottom of the article.) Those are the three elements that create an independent clause. What do those elements mean?
The subject is the thing taking action in the sentence.
The verb is the action being taken.
The object is the thing being acted upon.
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For example:
–Bobby kicks the ball. Here, “Bobby” is the subject, “kicks” is the verb,” and “the ball” is the object.
After you’ve underlined the subject, verb, and object in each independent clause, you can see how these two separate sentences can stand on their own, separated by a period.
Why connect them with a semicolon? Well, the two sentences might inform one other in a specific way that the semicolon can help to demonstrate. A writer might want to “close the gap” a little bit between the two independent clauses and demonstrate to readers that the ideas in the clauses should be read together instead of separately. The semicolon helps us to bridge that logical gap.
Exercise:
Now that you can see the pieces of an independent clause clearly, practice writing your independent clauses and linking them with a semicolon instead of separating them with a period.
Example:
–Maria loved Bobby; she didn’t want to live without him.
–The octopus is a magical animal; it can change its color depending on its surroundings.
–Roberta never skips breakfast; it’s the most important meal of the day, after all.
Take a look at your semicolon sentences. Why did you connect your independent clauses the way that you did? If you can give yourself a simple answer, it might help you to understand why another writer would do the same thing.
Rule 4: Separate two independent clauses with a comma and conjunction
As we showed in the previous rule, when you’re separating two independent clauses with a semicolon, you don’t need to use a conjunction like “and,” “or,” or “but.”
If, however, you have two independent clauses, and you want to show the relationship between them directly, you can separate them simply with a comma and a conjunction.
Examples:
–The road is long, but the journey is worthwhile.
–Everyone at the party liked the music, but the DJ decided to change things up anyway.
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
–My partner and I are happy in our relationship, and we’re talking about moving in together.
Hint: When you see a semicolon separating two independent clauses, you can simply take it out and replace it with a comma and a conjunction (and, but, or). And vice versa!
In other words, when combining independent clauses: ; = , + and/but/or
How easy is that?
Rule 5: Using commas to set off dependent clauses and modifiers
We’ve taken a look at how semicolons and commas can separate two independent clauses, but what do we do when the parts of a sentence can’t stand on their own? When you see that one part of the sentence couldn’t stand on its own as a complete sentence, you’re looking at something called a dependent clause or a modifier.
Examples:
–Given the state of global affairs, international travel has become difficult.
–When George gets angry, his mother puts him into a timeout.
–Flustered, I left the stage after making several mistakes in my speech.
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
–Since 2020, prices of goods and services have increased tremendously.
You can see that the words “Given the state of global affairs,” “When George gets angry,” “Flustered,” and “Since 2020” cannot stand on their own as independent clauses. That means they are dependent clauses, they depend on the information in the independent clause in order to exist as a part of the sentence.
Their purpose in these sentences is to either modify or supply additional information to the independent clause that follows.
When you’re taking the SAT and ACT, you want to remember that you need to place a comma after these dependent clauses and modifiers.
Why?
You can remember this simple rule by trying to read the sentences straight through without pausing after the dependent clauses and modifiers. It’s almost impossible to do. Again, we want to indicate a pause between dependent and independent clauses so that readers—when they approach those moments for the first time in a text—don’t get confused and muddle all the words together.
Rule 6: When to set off appositives with commas (and when not to)
An appositive is a noun or pronoun that serves to define or refine a noun or pronoun that comes before or after it. Sometimes a pronoun will take the form of a title, a nickname, or a simple explanation.
We’ll put the initial noun or pronoun in italics and the appositive will be underlined.
Sometimes you need to place commas around an appositive.
Examples:
–The Pittsburgh Steelers, a popular football team, are playing very badly this season.
–The first woman to attempt to fly around the world, Amelia Earhart, was never seen again.
–Franklin Delano Roosevelt, the 32nd president of the United States, was paralyzed from the waist down and relied on a wheelchair.
Sometimes you don’t need to put commas around an appositive.
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Examples:
–My college roommate Dave was also my best friend.
–LuAnna’s mother Rebecca is a wonderful cook.
–The children’s book company Scholastic often holds book fairs for kids.
What’s the difference? It’s pretty simple, but also maybe a little counterintuitive.
- When the sentence would otherwise be complete without the appositive, you need to put commas around it.
- When the original noun or pronoun is too vague and the appositive provides the necessary clarification to make the sentence work, you do not place commas around it.
Exercise:
Make a list of three people who you know and their relationship to you. Then, write some sentences with their name and appositive. Is the appositive necessary to make the sentence make sense? If so, don’t put commas around it.
Now, make a list of three celebrities or other famous figures like politicians. Include a brief description of those people. Now, write a sentence about each person. Is the appositive necessary to include? If not, put commas around it.
Rule 7: Separate modifying information with an em-dash
As a writer, I would be remiss if I didn’t tell you that the em-dash is my favorite form of punctuation. It’s a big line that lets you throw some weight around in your writing, but it is, sadly, often misunderstood.
But the em-dash is simple—you don’t need to overthink it!
An em-dash can be used in the following ways:
- To replace the words “it is,” “they are,” or in some places where you might use a colon
- For example: Losing weight can involve lots of steps, but there’s a simple way to start—calories in, calories out.
- To replace parenthesis
- For example: Nothing Patricia said during the trial was surprising—nothing she said ever surprised the judge—but she still managed to be found guilty.
- To interrupt dialogue
- For example: Lauren was so excited to ask Georgia out.
“I was just wondering if you wanted to—”
“Sorry Lauren—one sec—my boyfriend is calling.”
SAT & ACT Punctuation Rules – Cheat Sheet & Practice (Continued)
How else can you think about the em-dash? They are used where commas or parentheses can be used to set off parenthetical information in a sentence. The em-dash is used to link a dependent clause to the end of an independent clause—especially to add emphasis. (The previous sentence is an example!)
Note: Don’t confuse em-dashes with hyphens. Hyphens use a single keystroke to separate things like compound words (ex-husband, co-worker, corn-fed), number ranges (from ages 18-24), and written out numbers between 21 and 99 (twenty-one and ninety-nine).
If you want to use an em-dash, though, most word processors will turn two hyphens into a dash if you type them back-to-back without spaces around the words.
The Last Word:
When it comes to punctuation on the SAT and ACT, we’re hoping this cheat sheet will help you understand the grammar rules you need to follow while getting some much-needed punctuation practice. Remember that, in the end, punctuation rules aren’t here to confuse you; they’re meant to help you better understand the sentences that you write and read. Good luck!
*Exercise Answers:
Subject
Verb
Object
Sentence 1: For some reason, though, these two sentences really want to be attached to one another; they want to be one long sentence.
Sentence 2: Semicolons are the relationship glue that serves to shove together two independent clauses that might otherwise be separated by a period; you decide when those clauses belong together.
Additional Resources
